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225 Rebuild
https://www.slantsix.org/forum/viewtopic.php?t=68299		 Page 1 of 1
Author:  DartCon [ Fri Jul 25, 2025 4:57 pm ]
Post subject:  225 Rebuild
I am rebuilding my 225 Slant Six. I am new here so I will put my intro here as well.

I bought a 1966 Dodge Dart Convertible when I was 19. I drove it for a couple years and gave it to my parents. They gave it to my sister and it hasn’t been driven since I owned it. They recently called me and said they were thinking of giving it away. I’ve wanted it all this time so I asked if I could have it back. Lucky me!

So, today I went into the trailer and decided to start on pulling out the engine in pieces. They said I could work on it there as long as something is happening. Now that I started they are going to let me use their garage to get it going.

I want to get the HP as close to 200 as possible without going too too crazy, but I realize there will be some crazy. What do you all recommend? I have no A/C or power steering.

Pictures coming soon.

Image
Author:  MadScientistMatt [ Sat Jul 26, 2025 11:19 am ]
Post subject:  Re: 225 Rebuild
200 hp naturally aspirated is going to be a bit high strung; 200 hp with forced induction is likely to be fairly docile but expensive. What's your intended use?
Author:  Rick Covalt [ Sat Jul 26, 2025 2:29 pm ]
Post subject:  Re: 225 Rebuild
Is it an automatic or manual? You can get away with a lot bigger cam with a manual than an automatic, unless you want to change to a high stall speed convertor also. Your going to need a pretty large cam and a good flowing cylinder head to get where you want to go.
Author:  SlantSixDan [ Sun Jul 27, 2025 10:11 am ]
Post subject:  Re: 225 Rebuild
Quote:
I want to get the HP as close to 200 as possible
Why? Where does that number come from?

It's fun to think about big (or bigger-than-stock) numbers, but it is the wrong way to go about what you're trying to do, which sounds like you want the car to be quicker and faster. Read this; you've got some homework to do before pickin' up wrenches or plunkin' down money.
Author:  DartCon [ Mon Jul 28, 2025 4:09 am ]
Post subject:  Re: 225 Rebuild
Thanks for the replies. I’ll try to answer all of the questions.
Quote:
200 hp naturally aspirated is going to be a bit high strung; 200 hp with forced induction is likely to be fairly docile but expensive. What's your intended use?
This will hopefully answer some of SlantSixDan’s question as well. 200 hp is pretty arbitrary so please forgive me. I have a 2024 Ford Ranger that get 300 hp and I like the ease of merging and getting out of people’s way. The Dart is like 1k lbs lighter so I figured it didn’t require as much hp and torque.

I haven’t driven the Dart in 20+ years but I don’t remember having a hard time getting out of parking lots and into traffic, but I was 19 and probably not that concerned with it.

So, main things. I would eventually need it to go 80 mph comfortably, but that won’t be often and I won’t be doing that until I can make it as safe as possible and still realize it’s not very safe. I want to be able to get up to speed, 45-60 mph for local traffic, at a decent rate but not a race car. I would also like to be able to use unleaded 87 octane, if possible. I want to put power disc brakes on and possibly different bolt pattern to make finding wheels easier down the road.

I hope that answers it?
Quote:
Is it an automatic or manual? You can get away with a lot bigger cam with a manual than an automatic, unless you want to change to a high stall speed convertor also. Your going to need a pretty large cam and a good flowing cylinder head to get where you want to go.
It’s an automatic, it probably needs refreshing a bit before driving as well.
Quote:
Quote:
I want to get the HP as close to 200 as possible
Why? Where does that number come from?

It's fun to think about big (or bigger-than-stock) numbers, but it is the wrong way to go about what you're trying to do, which sounds like you want the car to be quicker and faster. Read this; you've got some homework to do before pickin' up wrenches or plunkin' down money.
I get where you are coming from. I haven’t purchased anything, but I am taking things apart engine wise to see what I have going on. I read the link you posted. All good info there.

With everything I mentioned above, it sure sounds like some improvement over stock might be all I am looking for, but I am not sure how much.
Author:  SlantSixDan [ Mon Jul 28, 2025 4:01 pm ]
Post subject:  Re: 225 Rebuild
Quote:
This will hopefully answer some of SlantSixDan’s question as well. 200 hp is pretty arbitrary so please forgive me.
Nothin' to forgive, just don't lean so hard on horsepower numbers, which have only two real purposes: to sell new cars, and to fuel benchracing sessions.
Quote:
I would eventually need it to go 80 mph comfortably, but that won’t be often
I had no difficulty getting to 80 mph and staying there in a near-stock '62 Lancer and '65 D'Valiant. 225 engines, 1-barrel carburetors, automatic transmissions, 2.93 or 3.23 rear axles, and 195/75R14 or 205/70R14 tires. They weren't the quickest to get to 80, but neither did they take all day. Some not-very-involved, not-very-expensive upgrades made them both considerably quicker to get to 80, without creating new problems or gritchments.

Really, you don't need to deviate radically from stock to wind up with a car that gives suitably brisk driveability and runs quietly, dependably, and economically. Careful engine rebuild with a few tweaks and optimizations you can readily read about on here. Carefully-chosen camshaft; that won't be difficult to pick or get. Carefully-picked 2-barrel carburetor and associated parts. A good ignition system, which will not require spending hundreds of bucks on parts. A good exhaust system. Rear axle ratio and tire size matched to the speed range you'll most often be driving. Cooling, electrical, and other ancillary systems upgraded to keep up. And…that's it! Not as flashy as the magazine articles that read like a breezy grocery list of expensive components…but you'll have a better result.

Reason I'm harping on this maybe harder than warranted in your case is that we've had people on the forum here over the years who've read articles and browsed catalogues, bought a bunch of high-zoot parts for a bunch of money, absolutely sure they were gonna wind up with a car that would easily win the Stoplight Grand Prix all day, and instead what they wound up with was an unreliable, troublesome, annoying car that didn't run well at all, guzzled gasoline and money and time, and basically was a big disappointment…that is if it ever ran under its own power again.

You sound a lot more thoughtful about the whole thing, and that's going to serve you well.
Quote:
and I won’t be doing that until I can make it as safe as possible and still realize it’s not very safe.
DING DING DING DING! As I was saying, you sound unusually thoughtful. Start with this post on safety upgrades, and yeah, you're right about that second part of the equation, too (start @ 4th big paragraph).
Author:  Dart270 [ Thu Jul 31, 2025 11:40 am ]
Post subject:  Re: 225 Rebuild
Sounds like a fun project. I can talk in some detail about making a streetable 180-200 HP NA engine that will be fun and sensible. I have built MANY of these. Will reply more later. Biggest place to put in work and time is the cylinder head and raising the compression some.

Lou
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